Pore‐scale modeling of competition and cooperation of multispecies biofilms for nutrients in changing environments

Abstract

In this article, we developed a pore-scale model of integrated lattice Boltzmann method and cellular automata to investigate competitive growth of aerobic nitrite and ammonium oxidizers in a bioreactor. The results showed that inlet nutrient concentrations have significant effects on maximum biofilm concentration, ratio of microorganisms' concentrations, growth pattern, and time. The local availability of oxygen could control the competition, resulting in different growth patterns. The coexistence of ammonium and nitrite in same inlet zone increased not only the biofilm concentration (7%) but also the ratio of microorganisms' concentrations (36%).Although this coexistence decreased the total biofilm concentration in some cases, it increased the growth rate about 25%. Changes of the maximum biomass concentration could change biofilm concentration of about 40% and microorganisms' concentrations ratio of about 30%. This framework provides a powerful tool to improve our understanding of dynamic interdependency of many complex microbial consortia systems with environments. K E Y W O R D S ammonium oxidizer, biofilm competitive growth, cellular automata, lattice Boltzmann, nitrite oxidizer

Phenol biodegradation in a bioreactor considering different geometries and process parameters

“…In the shrinkage step, if 17 or 18 neighbors of a fluid grid are solid grids, this grid should be converted to a solid (biofilm) grid. In the detachment process, the biofilm in fluid grids could be removed from the domain due to shear stress as an external force that is calculated as 19,20 :…”

“…The biofilm growth is determined by 18–20 : where and are the inactivation coefficient and the biomass yield in reaction, respectively. In the LBM‐CA the local flow field and species concentration are calculated using LBM, then this data is used in CA to capture biofilm growth through several sub‐steps including microorganisms growth, detachment (due to shear stress, ), extra biomass transfer, and shrinkage.…”

Non-Invasive Measurement, Mathematical Simulation and In Situ Detection of Biofilm Evolution in Porous Media: A Review

“…It is therefore necessary to propose several hypotheses (such as the uniformity of the biofilm matrix, flow condition, and properties of the porous media) to simplify models according to different research purposes (output). Pore-scale models usually originate from the actual structures of porous media including the microfluidic flow cell [80][81][82][83][84], glass pore network models [52,85], and others [86][87][88][89][90][91]. Fluid flow and mass transport are modeled using continuous strategies based on Darcy's law and conservation laws.…”

“…This model simulates not only the multispecies biofilm formation at pore-scale, but also the biomass distribution and the contaminant removal rate. Most recently, a LB-DbM method was used to investigate the competition of biofilm growth in a bioreactor at the pore scale [84]. The effects of different nutrient ratios on population cooperation and competition were studied at constant flow rates and concentrations of species in 2D space.…”

Probing mutual interactions between Pseudomonas aeruginosa and Candida albicans in a biofabricated membrane-based microfluidic platform

“…Engineered microfluidic platforms have been demonstrated to be outstanding in analytical performance 23 as static gradient generators, 24,25 fluidic parameter measuring devices, 26,27 and point of care testing devices. 28,29 The application of microfluidics in studying polymicrobial biology has been vastly developed with the capability of studying mutual interactions at single cell level, 30 as multispecies biofilm reactor, 31 or as spatially defined microbial consortia. 32,33 These microfluidic platforms offer the capability for continuous imaging and assessment of the dynamics of microbial interactions at single-cell or population level 34 by culturing microbes either in a direct cell–cell contact manner, or in a physically separated environment that allows for chemical molecules to freely diffuse across porous structures such as membranes or hydrogels prefabricated or sandwiched in the devices.…”